Someone asked my this personally and I thought, instead of answering directly, I could write down what I know in a blog post. Note that this is my personal opinion, you might disagree and are welcome to provide suggestions in the comments.

So you started using Drupal or are already using it for quite some time to create websites. And you want to contribute something back because you can use Drupal and all these modules for free.

I am currently on position 15 of the top contributors for Drupal 7. That means that 81 of my patches were commited (which also means that I have written a lot more since many patches usually require multiple iterations until they are good enough). Because of that, I was mentioned in Dries Keynote presentation at DrupalCon SF and some other blogs (german only):

More than a year ago, I needed a module which allows users to send private messages for a newly created Drupal 6 website. So I stumbled over Privatemsg. However, back then, it was an early development release which missed many features, had some bugs and so on. So I decided to help improving it.

7 weeks ago and probably hundreds of patches later (but still no stable release!), litwol made me a co-maintainer of the module which allowed me to commit patches myself.

Yesterday was our last full day in Calgary and we went a bit sightseeing as we hadn't seen much of Calgary so far. First, we went up to the Calgary Tower where you have a nice view over Calgary in all directions. The tower is 191m high and we were able to use two tickets that belong to our Bed & Breakfast, so we saved the 13$ admission.

Later, we visited SAIT, the competitor village to check how their rooms are and how their condition was after the party-night :)

During the last two days, we could watch how the tasks and projects from the various competitors slowly (and sometimes amazingly fast) came to a finish. It was really interesting but especially today was very exhausting as I wanted to see as much as possible.

It went pretty well for Fabian on the third and fourth day, he had enough time to finish everything. However, it's really hard to compare the different websites as I have seen only bits and pieces of them during the short presentation.